Image hosting service Tumblr is banning all adult images of sex and nudity from 17th December 2018. This seems to have been sparked by the app being banned from Apple Store after a child porn image was detected being hosted by Tumblr. Tumblr
explained the censorship process in a blog post:

Starting Dec 17, adult content will not be allowed on Tumblr, regardless of how old you are. You can read more about what kinds of content are not allowed on Tumblr in our Community Guidelines. If you spot a post that you don't think belongs on
Tumblr, period, you can report it: From the dashboard or in search results, tap or click the share menu (paper airplane) at the bottom of the post, and hit Report.

Examples of exceptions that are still permitted are exposed female-presenting nipples in connection with breastfeeding, birth or after-birth moments, and health-related situations, such as post-mastectomy or gender confirmation surgery. Written
content such as erotica, nudity related to political or newsworthy speech, and nudity found in art, such as sculptures and illustrations, are also stuff that can be freely posted on Tumblr.

Any images identified as adult will be set as unviewable by anyone except the poster. There will be an appeals process to contest decisions held to be incorrect.

Inevitably Tumblr algorithms are not exactly accurate when it comes to detecting sex and nudity. The Guardian noted that ballet dancers, superheroes and a picture of Christ have all fallen foul of Tumblr's new pornography ban, after the images
were flagged up as explicit content by the blogging site's artificial intelligence (AI) tools.

The actor and Tumblr user Wil Wheaton posted one example:

An image search for beautiful men kissing, which was flagged as explicit within 30 seconds of me posting it.

These images are not explicit. These pictures show two adults, engaging in consensual kissing. That's it. It isn't violent, it isn't pornographic. It's literally just two adult humans sharing a kiss.

Other users chronicled flagged posts, including historical images of (clothed) women of colour, a photoset of the actor Sebastian Stan wearing a selection of suits with no socks on, an oil painting of Christ wearing a loincloth, a still of ballet
dancers and a drawing of Wonder Woman carrying fellow superhero Harley Quinn. None of the images violate Tumblr's stated policy.

Tumblr, after years of being a space for nsfw artists to reach a community of like-minded individuals to enjoy their work, has decided to close their metaphorical doors to adult content.

Solution Stop it. Let people post porn, it's 90% of the reason anybody is on the site in the first place. Or, if you really want a non-18+ tumblr, start a new one with that specific goal in mind. Don't rip down what people have spent years
working on.

The Free Speech coalition [representing the US adult trade] released the following statement regarding the recent announcement about censorship at Tumblr:

The social media platform Tumblr has announced that on December 17, it will effectively ban all adult content. Tumblr follows the lead of Facebook, Instagram, YouTube and other social media platforms, who over the past few years have meticulously
scrubbed their corners of the internet of adult content, sex, and sexuality, in the name of brand protection and child protection.

While some in the adult industry may cheer the end of Tumblr as a never-ending source of free content, specifically pirated content, it is concerning that of the major social media platforms, only Twitter and Reddit remain in any way tolerant of
adult workers -- and there are doubts as to how much longer that will last.

As legitimate platforms ban or censor adult content -- having initially benefited from traffic that adult content brought them -- illegitimate platforms for distribution take their place. The closure of Tumblr only means more piracy, more
dispersal of community, and more suffering for adult producers and performers.

Free Speech Coalition was founded to fight government censorship -- set raids and FBI entrapment, bank seizures and jail terms. The internet gave us freedom from much that had plagued us, particularly local ordinances and overzealous prosecutors.
But now, when corporate censors suspend your account, the only choice is to abandon the platform 203 there is no opportunity for arbitration or appeal.

When companies like Google and Facebook (and subsidiaries like YouTube and Instagram) control over 70% of all web traffic, adult companies are denied a market as effectively as a state-level sex toy ban. And when sites like Tumblr and Twitter can
close an account with millions of followers without warning, the effect is the same on a business -- particularly a small, performer-run one -- as an FBI seizure.

As social media companies become more powerful, we must demand recourse, but we also must look beyond our industry and continue to build alliances -- with women, with LGBTQ groups, with sex workers and sex educators, with artists -- who
implicitly understand the devastating effect of this new form of censorship.

These communities have seen the devastation wreaked when platforms use purges of adult content as a sledgehammer, broadly banning sexual health information, vibrant communities based around non-normative genders and sexualities, resources for sex
workers, and political and cultural commentary that engages with such topics.

The loss of these platforms isn't just about business, it's about the loss of vital communities and education -- and organizing. We use these platforms not only to grow our reach, but to communicate with one another, to rally, to drive awareness
of issues of sex and sexuality. They have become a central source of power. And today, we're one step closer to losing that as well.

Since Tumblr announced its porn ban in December, many users reacted by explaining that they mainly used the site for browsing not-safe-for-work content, and they threatened to leave the platform if the ban were enforced. It now appears that many
users have made good on that threat: Tumblr's traffic has dropped nearly 30% since December.

The ban removed explicit posts from public view, including any media that portrayed sex acts, exposed genitals, and female-presenting nipples.